9.2 ixgbe tx queue hang

[Rick Macklem]

Christopher Forgeron wrote:
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> On Tue, Mar 25, 2014 at 8:21 PM, Markus Gebert <
> markus.gebert at hostpoint.ch > wrote:
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> Is 65517 correct? With Ricks patch, I get this:
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> dev.ix.0.hw_tsomax: 65518
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> Perhaps a difference between 9.2 and 10 for one of the macros? My
> code is:
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> ifp->if_hw_tsomax = IP_MAXPACKET - (ETHER_HDR_LEN +
> ETHER_VLAN_ENCAP_LEN);
> printf("CSF - 3 Init, ifp->if_hw_tsomax = %d\n", ifp->if_hw_tsomax);
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The difference is simply that IP_MAXPACKET == 65535, but I've been using
32 * MCLBYTES == 65536 (the latter is the amount of data m_defrag() can
squeeze into 32 mbuf clusters).

ie. I've suggested:
    ifp->if_hw_tsomax = min(32 * MCLBYTES - (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN),
         IP_MAXPACKET);
- I put the min() in just so it wouldn't break if MCLBYTES is increased someday.

rick

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> (BTW, you should submit the hw_tsomax sysctl patch, that's useful to
> others)
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> Also the dtrace command you used excludes 65518...
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> Oh, I thought it was giving every packet that is greater than or
> equal to 65518 - Could you show me the proper command? That's the
> third time I've used dtrace, so I'm making this up as I go. :-)
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